title: Advantages of pinhole collimator double-phase scintigraphy with 99mTc-MIBI in secondary hyperparathyroidism.
abstract: OBJECTIVE
  The aim of the study was to determine if pinhole collimator-acquired images can improve the detection of hyperfunctioning parathyroid glands in patients with secondary hyperparathyroidism.
  
  
  METHODS
  Forty-two patients being treated with cinacalcet for secondary hyperparathyroidism were studied prospectively. Patients were divided into 2 groups according to their levels of parathyroid hormone (PTH), the hormone that defines response to treatment: "responders" (PTH <300 pg/mL) and "nonresponders" (PTH ≥ 300 pg/mL). Double-phase scintigraphy using 888 MBq of (99m)Tc-MIBI was used to acquire early and late parallel-hole and pinhole collimator images. Neck ultrasonography was performed on all patients to identify intrathyroid nodules. All focal uptake in any of the acquired scintigraphic images was considered positive.
  
  
  RESULTS
  The responder group included 24 patients, whereas 18 patients were considered as nonresponders. At least 1 parathyroid gland with (99m)Tc-MIBI uptake was detected in 33 of 42 patients, with a total of 50 parathyroid glands located. We found significant differences between the detection rates of late pinhole collimator and the late parallel-hole images (74% vs 48%, P = 0.0036). This detection rate was highest with late parallel-hole images in the nonresponder group (89%).
  
  
  CONCLUSIONS
  The late pinhole collimator acquisition showed the highest detection rate of hyperfunctioning parathyroid glands using (99m)Tc-MIBI scintigraphy in secondary hyperparathyroidism patients treated with cinacalcet.
authors.affiliation: From the *Nuclear Medicine Department, Hospital Clínic; †IDIBAPS (Institut d'Investigacions Biomèdiques Agustí Pi i Sunyer), University of Barcelona; and ‡Renal Transplant Unit and §Radiology Department, Hospital Clínic, Barcelona; ∥Radiology Department, University of Southern California, Los Angeles, CA; and ¶Nuclear Medicine Department, Santa Maria della Misericordia Hospital, Rovigo, Italy.
authors.forename: David
authors.initials: D
authors.lastname: Fuster
authors.forename: Marina
authors.initials: M
authors.lastname: Depetris
authors.forename: José-Vicente
authors.initials: JV
authors.lastname: Torregrosa
authors.forename: Mattia
authors.initials: M
authors.lastname: Squarcia
authors.forename: Raphael P
authors.initials: RP
authors.lastname: Paschoalin
authors.forename: Maria
authors.initials: M
authors.lastname: Mayoral
authors.forename: Ulises
authors.initials: U
authors.lastname: Granados
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Colletti
authors.forename: Domenico
authors.initials: D
authors.lastname: Rubello
authors.forename: Francesca
authors.initials: F
authors.lastname: Pons
mesh_terms: D005260:Female; D006801:Humans; D006962:Hyperparathyroidism, Secondary / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010280:Parathyroid Glands / Q000000981:diagnostic imaging; D011877:Radionuclide Imaging / Q000295:instrumentation*; D017256:Technetium Tc 99m Sestamibi; D014463:Ultrasonography
chemical_list: D017256:Technetium Tc 99m Sestamibi